Properties of dispersion-managed soliton are analyzed. Dispersion-managed soliton propagation and interaction in optical fibers are numerically simulated. If there is little difference between local dispersion and average dispersion, it is better to insert the pulse with shape as hyperbolic secant. If increasing the differences of local dispersion and average dispersion, the shape of the pulse will transform as Gaussian. Dispersion become the main factor of dispersion-managed soliton interaction.